1. Field of the Invention
The present invention relates to a vehicle suspension apparatus and, more specifically, to an improvement in suspension for reducing a nose dive generated in a vehicle body especially when the vehicle is braked.
2. Description of the Related Art
Japanese Utility Model Disclosure (Kokai) No. 60-119631 discloses a conventional suspension apparatus for reducing a nose dive generated in a vehicle body by supplying a fluid to front-wheel fluid spring chambers while exhausting a fluid from rear-wheel fluid spring chambers when the deceleration of the vehicle is large. In such a suspension apparatus, since compressed air is consumed every time control for reducing a nose dive is performed, the operation frequency of a compressor is increased. As a result, durability of the compressor is degraded. In addition, since the control is performed in the same manner regardless of the magnitude of a deceleration in a braking operation, passengers may feel uncomfortable.
Japanese Patent Disclosure (Kokai) No. 61-44014, therefore, discloses a suspension apparatus which is designed to perform two-stage supply/exhaust air control when a brake pedal is depressed and when a deceleration exceeds a set value.
In this apparatus, however, since the first stage control is performed when the brake pedal is depressed, a vehicle position error may occur by unnecessary control or durability of each part may be degraded.